I've seen a large butterfly chase a different kind of butterfly around - it may, or may not have been territoriality. Is there a minimum scale of size, sentience(?) an organism must attain to exhibit territoriality?

1 Answer
1

With some bacteria (e.g.. Bacillus subtilis) when food gets scarce they will start trying to kill their neighbors. (See this arstechnica article) This appears to be a fight to the death between children and parents. That's a kind of territorial behavior, selectively applied only when there are not enough resources to go around. As there is no "recognition" of a specific territory being defended, just wherever the bacteria is currently, this might not meet a strict definition of territorial behavior. But the only thing simpler than bacteria are viruses.

Come to think of it, I bet there are viruses that, once they infect a host cell, will change the cell's membrane or metabolism in a way that reduces its chance of being infected again by a similar virus. Such 'behavior' could be compared to defending a breeding ground. Can't find any examples though.

$\begingroup$+1 for the viruses. pnas.org/content/109/44/18078 ;)... But I don't really think that article is really an example of territoriality.$\endgroup$
– EekhoornNov 26 '12 at 10:03

$\begingroup$Without some selective defense of something, I don't see any indication that the small virus behaves territorially. But a virus that infects a virus is still a pretty neat thing.$\endgroup$
– Stuart R. JefferysNov 26 '12 at 14:29

$\begingroup$This is pretty cool; I've +1'ed it for now. If another answer doesn't come through in a day let me then flag this as correct.$\endgroup$
– EveryoneNov 26 '12 at 16:28